The present invention relates to mounting apparatus for semiconductor components and, more particularly, to mounting apparatus for mounting semiconductor components on substrates.
In the past, various devices have been developed for mounting electronic components to substrates. For instance, U.S. Pat. Nos. 5,018,936 and 5,033,783 disclose one type of mounting apparatus equipped with a mounting head, which is provided with a suction nozzle assembly at one end thereof, and a recognition camera, which is mounted above the mounting head opposite the suction nozzle assembly. The suction nozzle assembly is adapted to pick up electronic parts and is made from a light transmitting material such that the picked-up parts can be viewed by the camera through the suction nozzle assembly for determining their shape and position. In this manner, the mounting apparatus eliminates the need to provide a camera adapted to be positioned below the suction nozzle assembly for viewing the images of the picked-up parts.
While the mounting apparatus described above facilitates an electronic part mounting process, it has various shortcomings and disadvantages. For instance, it is believed that the mounting apparatus is not adapted for precise placement of microscopic objects, such as semiconductor components, on other objects (e.g., such as substrates) Moreover, because the camera is not incorporated into the mounting head, the camera needs to be mounted to the mounting apparatus separately from the mounting head, thereby requiring an additional effort to mount the camera to the mounting apparatus and then to align the camera with the mounting head. In addition, because the camera and the mounting head are independent and discrete from one another, an additional mechanism (e.g., a mounting bracket) needs to be provided for moving the camera conjointly with the mounting head. Further, because the suction nozzle assembly is mounted to the mounting head via a retainer member, detachment of the suction nozzle assembly from the mounting head involves an additional step (i.e., removal of the retainer member from the suction nozzle assembly).
The present invention overcomes the disadvantages and shortcomings of the prior art discussed above by providing a new and improved mounting apparatus for semiconductor components. More particularly, the mounting apparatus includes a mounting head and a suction-operated gripping mechanism for selectively gripping an object (e.g., a semiconductor component or die) positioned adjacent one side of the gripping mechanism. A suction-operated attaching mechanism is also provided for selectively and removably attaching the gripping mechanism to the mounting head, whereby the gripping mechanism is removable from the mounting head and is hence replaceable. The mounting apparatus also has a viewing mechanism, including a camera, for viewing an object gripped by the gripping mechanism. The viewing mechanism is located on an opposite side of the gripping mechanism. The gripping mechanism has a light-transmitting portion positioned in such a manner that an object gripped by the gripping mechanism can be viewed by the camera through the gripping mechanism.
The mounting apparatus constructed in accordance with the present invention is adapted for picking up and precisely placing microscopic devices, such as semiconductor devices and optoelectronic dies, to other semiconductor devices (e.g., substrates). The mounting apparatus is also adapted for picking up and precisely placing large objects with the same mounting apparatus.
The mounting apparatus is also adapted for high accuracy placement of semiconductor components or dies on substrates. For instance, high accuracy die placement is achieved by providing the mounting apparatus with moving and/or adjusting mechanisms adapted for accurate alignment of a semiconductor component relative to a substrate in all directions (i.e., X, Y, Z and xcex8 directions). In this regard, the moving and adjusting mechanisms include an X-Y stage adapted to support thereon a substrate and adapted to move relative to the mounting head in the X and Y directions, thereby eliminating the need to move the mounting head in the X and Y directions after picking up a semiconductor component and hence minimizing inadvertent movement of the semiconductor component.
The viewing mechanism also facilitates high accuracy die placement. More particularly, the viewing mechanism is adapted for simultaneously or sequentially viewing (i.e., identifying) fiducial marks or other repeatable patterns on semiconductor components and on substrates. Fiducial marks can be viewed or identified by the camera with a single field of view or multiple fields of view. For instance, highly accurate die placement requires a high powered magnification for the camera, causing the field of view of the camera to decrease. An adjustment mechanism is provided for the viewing mechanism for adjusting the position of the camera in the X, Y and Z directions. In this manner, when one or more fiducial marks lies outside of the field of view of the camera, the position of the camera can be adjusted during die placement to bring such fiducial marks into the field of view of the camera. The mounting head can also include a rotatable mechanism for adjusting, if necessary, the angular orientation of a semiconductor component relative to the camera.
In accordance with one feature of the present invention, the mounting apparatus is provided with a force/load gauge for measuring the force being applied to the mounting head by an associated chuck during a die placement process and for providing a feedback to an operator or a controller. The force/load gauge is mounted within the mounting head.
Another feature of the present invention involves providing the mounting apparatus with a lighting mechanism. For instance, the mounting apparatus can be equipped with dark field and/or bright field illumination mechanisms. Fiber optic lights can also be used in combination with the mounting apparatus.
The mounting apparatus of the present invention is adapted for numerous applications. For instance, the mounting apparatus can be adapted for hand-held application (i.e., the mounting apparatus can be designed to be hand-held). The mounting apparatus can also be adapted for fully or partially automated die placement.